bullet Sensors & Transducers Journal

    (ISSN 1726- 5479)


2007 e-Impact Factor

25 Top Downloaded Articles

Journal Subscription 2008

Editorial Calendar 2008

Submit an Article

Editorial Board

Current Issue

Sensors and Transducers journal's cover


Sensors & Transducers Journal 2007

2000-2002 S&T e-Digest Contents

2003 S&T e-Digest Contents

2004 S&T e-Digest Contents

2005 S&T e-Digest Contents

2006 S&T e-Digest Contents


Best Articles 2007




Vol. 93, Issue 6, June 2008, pp.57-68




Color Signature of Current: a Novel Concept for Current Level Indication


Sarbani CHAKRABORTY, Satish Chandra BERA*


Department of Electrical and Electronics Engineering, Birla Institute of Technology,

Mesra, Ranchi-835215, Jharkhand, India,

E-mail: sarbaniry@yahoo.com, schakraborty@bitmesra.ac.in

*Instrumentation Engineering Section, Department of Applied Physics,

University of Calcutta, 92 APC Road, Calcutta 700009, India

E-mail: scb152@indiatimes.com



Received:  20 April 2008   /Accepted: 24 June 2008   /Published: 30 June 2008


Abstract: When a polarized polychromatic beam passes through a magneto-optic medium placed in a magnetic field the constituent spectral components suffer different amount of Faraday rotation due to wavelength dependent Verdet constant. As a result, the change in the color of the resultant beam with the change of the magnetic flux density or current level (linearly related to magnetic flux density) can be detected when it passes through an analyzer. The color of the resultant beam depends on the magnetic flux density, orientation of the transmission axis of the analyzer, state of polarization of the input polarized polychromatic beam, the spectral intensity distribution of the source and the polarization properties of the Faraday medium and other optical components involved in the system. In the present article the theoretical study of color difference in CIELAB color space shows considerable color change with the change in current strength passing through a solenoid coil where the input light is linearly polarized polychromatic beam passing through a magneto-optic (Terbium Doped Glass (TDG)) medium placed inside the solenoid coil. Considering the limitations of experimental determination of color difference in CIELAB space, a color matching scheme is developed in HSL color space for fast detection of current level. This scheme is envisaged to be suitable for detection of current level within stipulated tolerance by utilizing color image processing techniques in machine vision applications.


Keywords: Polarization, Polychromaticity, Magneto-optic element, Color image processing, Machine Vision


 Acrobat reader logo Click <here> or title of paper to download the full pages article (1.13 M)





1999 - 2008 Copyright , International Frequency Sensor Association (IFSA). All Rights Reserved.

Home - News - Links - Archives - Tools - Standardization - Patents - Marketplace - Projects - Wish List - Subscribe - Search - e-Shop - Membership

 Members Area -Sensors Portal -Training Courses - S&T Digest - For advertisers - Bookstore - Forums - Polls - Sensor Jobs - Site Map